Before the last
joint meeting of the A.S.A.-EX.S., I had requested Dr. Gordon H. Clark of Butler
University to prepare another column for the Journal. His observation of the
proceedings at Goshen College stimulated the following comments on
"Observation."Observation
Gordon H. Clark

English
speaking people, even those who use correct grammar and an attractive style,
often do not know the rules of grammar as well as a foreigner who has
deliberately studied them. An accomplished musician also and a skillful painter
may not know very much about art. Similarly a practicing and brilliant scientist
may be relatively hazy on the grammar of science.

At the last joint meeting of the ASA-ETS one of the scientists asserted that
observation was the authority in
science. Two or three other speakers confirmed the idea that science depends on
observation, and in a context that suggested that observation is the only basis
and authority in science. Since such an idea carries with it important
conclusions for the philosophy of science and strongly colors one's views as to
the relation of science to theology, this paper will advance certain negative
considerations.

To avoid
misunderstanding at the outset, it must be said that this argument does not deny
that observation is an authority in science. The thesis is that observation is
not the sole authority. There are other factors, other grammatical rules, other
bones and sinews that determine the form of scientific law.

The
simplest example is no doubt the use of the arithmetic mean. After the
experimenter collects a list of readings, he adds them and divides by the number
of readings. No observational necessity dictates this step. So far as
experimentation is concerned, he could have used the mode or the median, instead
of the mean. Similarly, to take a slightly more complex example, when a
scientist uses the standard deviation, he squares the x's; but there is no
observational necessity that prevents him from cubing them. If the scientist
should reply that the standard deviation ties in with the principle of least
squares, one need -only ask him why he does not choose to use the principle of
least cubes. Many other examples could be mentioned. Now, since the laws of
science depend on the mathematical forms chosen, and since different
mathematical forms could be chosen, it follows that scientific law does not
depend wholly on observation.

Ordinarily
one might say that observation places certain limits upon the range of choice.
The arithmetic mean leads to the use of a plus or minus variable error. Such
values, transferred to graphs, become areas and not points. Through a series of
areas any one of an infinite number of curves can be passed. Therefore there is
no observational necessity for choosing one scientific law rather than any other
that passes through these areas. Although this permits an infinite range of
choice, it also excludes an infinite range. Observation prohibits the choice of
a curve that falls outside the limits of the variable error. Hence observation
is an authority, even though it is not the authority.

But while
this is the ordinary situation, it is not always true that the scientist chooses
within the range of observation. Perhaps the most famous example is that of the
Copernican astronomy. When Copernicus resurrected the heliocentric theory of
Plato and Aristarchus, the Ptolmaic mathematics could more accurately predict
the positions of the planets than the heliocentric theory could. Moreover, the
heliocentric: theory implied a stellar parallax, and there was none observable.
To be sure, a stellar parallax was observed three hundred years later. But for
these three centuries the heliocentric theory made its way in spite of
observation. The charm of the mathematics overbalanced the force of the visible
data.

At the last
joint meeting of the ASA-ETS not only were there speakers from the physical
sciences, there were also representatives of the social sciences, and these too
stressed observation. Whether or not these speakers actually asserted that
observation is the only authority in science is beside the present point; the
present point is that social science can even less proceed on blind trust of
observation.

One
difficulty in sociology is that so few fundamental measurements can be made. The
units are so often very poorly defined, of not defined at all. Therefore
numerical laws and derivative measurements are impossible.

But the
factor which removes sociology from sole dependence on observation, and which
obviously than in the case of physics, is the prominent part played by ethical
norms. No one is satisfied to count the number of divorces or the number of
burglaries. Everyone, and sociologists above all, rush to explain the cause and
the cure. But these proposals are essentially ethical and political principles.
They are assertions of what ought to be; they are not descriptions of what is.
For this reason ethics is not an observational science. Norms cannot be obtained
by descriptive methods. Yet so often a sociologist refuses to justify the norms
of which he makes use.

There are
some philosophers who do indeed claim to raise norms on a descriptive basis. The
argument against them cannot be detailed here. My ideas on this point can
be found in the items mentioned in the footnote.,, But enough has been said, I
hope, to establish the need for a philosophy of science that will define the
role of observation and indicate what other factors must be brought in play.